Flip chip mounting method, flip chip mounting apparatus and flip chip mounting body

ABSTRACT

A flip chip mounting method includes holding a circuit board ( 213 ) and a semiconductor chip ( 206 ), aligning the circuit board ( 213 ) with the semiconductor chip ( 206 ) while holding them with a predetermined gap therebetween, heating the circuit board ( 213 ) or the semiconductor chip ( 206 ) to a temperature at which solder powder in a solder resin composition ( 216 ) formed of solder powder ( 214 ) and a resin ( 215 ) is melted, supplying the solder resin composition ( 216 ) by a capillary phenomenon, and curing the resin ( 215 ), wherein the melted solder powder ( 214 ) in the solder resin composition ( 216 ) is moved through the predetermined gap across which the circuit board ( 213 ) and the semiconductor chip ( 206 ) are held, and self-assembled and grown, whereby the connection terminals ( 211 ) and the electrode terminals ( 207 ) are connected to each other electrically. According to this configuration, a flip chip mounting method having high productivity and reliability, which enables a next generation semiconductor chip to be mounted on a circuit board, a mounted body thereof, and a mounting apparatus thereof are provided.

TECHNICAL FIELD

The present invention relates to a flip chip mounting method formounting a semiconductor chip on a circuit board, and in particular, toa flip chip mounting method, a flip chip mounting apparatus, and a flipchip mounted body, which are adaptable to even a semiconductor chip witha narrower pitch and have high productivity and connection withexcellent reliability.

BACKGROUND ART

In recent years, with a trend toward a higher density and a higherdegree of integration for a semiconductor integrated circuit(hereinafter, abbreviated as a “semiconductor”) chip used for electronicequipment, the number of pins of electrode terminals of a semiconductorchip has been increased and the pitch thereof has been decreasedrapidly. For mounting these semiconductor chips on circuit boards, flipchip mounting is used widely in order to decrease a wiring delay.

In the flip chip mounting, solder bumps generally are formed onelectrode terminals of the semiconductor chip, which then are joined toconnection terminals formed on the circuit board at one time.

However, in order to mount a next-generation semiconductor chip havingmore than 5,000 electrode terminals on a circuit board, it is necessaryto form solder bumps that correspond to a narrow pitch of 100 μm orless, but it is difficult to adapt to it with a current technique forforming solder bumps.

Moreover, since it is necessary to form a large number of solder bumpsthat correspond to the number of the electrode terminals, theproductivity has to be raised by shortening a mounting cycle for eachchip, along with the reduction in cost.

Similarly, in the semiconductor chip, the increase in the number of theelectrode terminals has brought about a transition fromperipheral-arranged electrode terminals to area-arranged electrodeterminals.

Moreover, due to the demands for a higher density and a higher degree ofintegration, a limitation on a semiconductor process is expected todevelop from 90 nm to 65 nm and further to 45 nm. In order to adapt tothis, there is a strong demand for an insulating material having a lowdielectric constant, and for the purpose of satisfying the demand, anattempt has been made so as to introduce a porous insulating material.However, in order to use a porous insulating material, mounting at a lowload is required so as to alleviate the damage to the insulatingmaterial and an active circuit. Furthermore, mounting at a low load alsois desired in order to prevent a semiconductor chip from being brokenduring handling due to the thinning of the semiconductor chip.Particularly, in the case of the area arrangement, it is necessary toconstitute electrodes on an active circuit, so that there is a demandfor a mounting method at a lower load.

Thus, there is a demand for a flip chip mounting method that isadaptable to a decrease in thickness and an increase in density due tothe future development of the semiconductor process.

Conventionally, as a technique for forming solder bumps, plating, screenprinting, and the like have been developed. The plating is suitable fora narrow pitch, but has a problem in productivity due to its complicatedprocess. On the other hand, the screen printing has excellentproductivity, but is not suitable for narrowing a pitch because of theuse of a mask.

In the light of the problems described above, several techniques forforming solder bumps selectively on electrode terminals of asemiconductor chip or connection terminals on a circuit board have beendeveloped recently. These techniques not only are suitable for formingfine solder bumps but also have excellent productivity because they canform the solder bumps all at one time, and attract attention astechniques that are adaptable to the mounting of the next-generationsemiconductor chip on the circuit board.

As one of these techniques, there is the following technique: a solderpaste, which is a mixture of solder powder and flux, is applied whollyonto a circuit board whose surface is provided with connectionterminals, and the circuit board is heated so as to melt the solderpowder, whereby solder humps are formed selectively on the connectionterminals that have high wettability (see Patent Document 1, forexample).

There also is a technique called a super solder method. According tothis technique, a paste-like composition (chemical reactiondeposition-type solder) that contains an organic acid lead salt andmetallic tin as main components is applied wholly onto a circuit boardon which connection terminals are formed, and the circuit board isheated so as to cause a substitution reaction between Pb and Sn, therebydepositing a Pb/Sn alloy selectively on the connection terminals of thecircuit board (see Patent document 2, for example).

Conventional flip chip mounting further requires the step of injecting aresin called an underfill between the semiconductor chip and the circuitboard in order to fix the semiconductor chip on the circuit board, aftermounting the semiconductor chip on the circuit board on which solderbumps are formed. Because of this, there also have been problems of anincrease in the number of steps and a decrease in a yield.

Then, as a method for establishing an electric connection betweenelectrode terminals of the semiconductor chip and connection terminalsof the circuit board, which are opposed to each other, and fixing thesemiconductor chip onto the circuit board both at the same time, a flipchip mounting technique using an anisotropic electrically conductivematerial has been developed. In this technique, by supplying athermosetting resin containing electrically conductive particles betweenthe circuit board and the semiconductor chip, and then heating thethermosetting resin while applying a pressure to the semiconductor chipat the same time, it is possible to establish the electric connectionbetween the semiconductor chip and the circuit board and fix thesemiconductor chip to the circuit board at the same time (for example,see Patent Document 3).

However, in both of the method for forming solder bumps described inPatent Document 1 and the super solder method described in PatentDocument 2, since the paste-like composition simply is supplied onto thecircuit board by application, local variations in thickness andconcentration occur, resulting in variations in the solder depositionamount for individual electrode terminals and connection terminals.Consequently, it is not possible to achieve solder bumps with uniformheights. Also, in these methods, since the paste-like composition issupplied by application onto the circuit board whose surface is providedwith the connection terminals, namely, with projections or depressions,a sufficient amount of solder cannot be supplied onto the connectionterminals serving as the projections, making it difficult to achieve adesired solder bump height necessary for the flip chip mounting.

Moreover, in the flip chip mounting method described in Patent Document3, there are many problems in productivity and reliability that are tobe solved as described below.

First, since the electric conduction between the respective terminals isobtained by mechanical contact via the electrically conductiveparticles, it is difficult to achieve a stable conductive state. Second,since a distance varies depending upon an amount of the electricallyconductive particles that are present between the electrode terminals ofthe semiconductor chip and the connection terminals of the circuitboard, the electric connection is unstable. Third, in order to realizethe stable electric connection, crimping by pressing at a high pressure(load) is required, which is likely to break a semiconductor chip.

Patent Document 1: JP 2000-94179 A

Patent Document 2: JP 1(1989)-157796 A

Patent Document 3: JP 2000-332055 A

DISCLOSURE OF INVENTION

In order to solve the above problems, the present invention provides aflip chip mounting method, a flip chip mounting apparatus, and a flipchip mounted body which are capable of mounting a semiconductor chiphaving a number of electrode terminals on a semiconductor chip, and havehigh productivity and reliability.

A flip chip mounting method of the present invention for placing asemiconductor chip having a plurality of electrode terminals so that itis opposed to a circuit board having a plurality to connectionterminals, and connecting the connection terminals of the circuit boardelectrically to the electrode terminals of the semiconductor chip,includes: a holding step of holding the circuit board and thesemiconductor chip; an arrangement step of aligning the connectionterminals of the circuit board with the electrode terminals of thesemiconductor chip while holding the connection terminals and theelectrode terminals in a contact state, or aligning the connectionterminals of the circuit board with the electrode terminals of thesemiconductor chip while holding the connection terminals and theelectrode terminals with a predetermined gap therebetween; a heatingstep of heating at least the circuit board or the semiconductor chip toa temperature at which solder powder in a solder resin compositionformed of the solder powder and a resin is melted; a supply step ofsupplying the solder resin composition to the predetermined gap acrosswhich the circuit board and the semiconductor chip are held, from atleast one end face direction of the semiconductor chip by a capillaryphenomenon; and a curing step of curing the resin in the solder resincomposition, wherein in the supply step, the melted solder powder in thesolder resin composition is moved through the predetermined gap acrosswhich the circuit board and the semiconductor chip are held, and thesolder powder is self-assembled and grown, thereby connecting theconnection terminals electrically to the electrode terminals.

A flip chip mounting apparatus of the present invention for flip chipmounting a semiconductor chip on a circuit board includes: holding meansfor holding the circuit board and the semiconductor chip; arrangementmeans for aligning the connection terminals of the circuit board withthe electrode terminals of the semiconductor chip while holding theconnection terminals and the electrode terminals in a contact state, oraligning the connection terminals of the circuit board with theelectrode terminals of the semiconductor chip while holding theconnection terminals and the electrode terminals with a predeterminedgap therebetween; heating means for heating at least the circuit boardor the semiconductor chip to a temperature at which solder powder in asolder resin composition made of the solder powder and a resin ismelted; supply means for supplying the solder resin composition to thepredetermined gap across which the circuit board and the semiconductorchip are held, from at least one end face direction of the semiconductorchip by a capillary phenomenon; and curing means for curing the resin inthe solder resin composition.

A flip chip mounted body of the present invention includes: a circuitboard having a plurality of connection terminals; a semiconductor chiphaving a plurality of electrode terminals placed so as to be opposed tothe connection terminals; a solder layer that connects the connectionterminals of the circuit board electrically to the electrode terminalsof the semiconductor chip; and a first insulating resin covering atleast the solder layer and a second insulating resin covering the firstinsulating resin and fixing the circuit board and the semiconductor chipto each other.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A to 1C are cross-sectional process views showing a basicmechanism of a flip chip mounting method of the present invention.

FIGS. 2A to 2E are schematic cross-sectional process views illustratinga flip chip mounting method in Embodiment 1 of the present invention.

FIGS. 3A and 3B are plan views illustrating a method for supplying asolder resin composition in Embodiment 1 of the present invention.

FIGS. 4A and 4B are plan views illustrating a method for supplying asolder resin composition in Embodiment 1 of the present invention.

FIGS. 5A to 5E are schematic cross-sectional process views illustratinga flip chip mounting method in Embodiment 2 of the present invention.

FIGS. 6A to 6E are schematic cross-sectional process views illustratinga flip chip mounting method in Embodiment 3 of the present invention.

FIGS. 7A to 7E are schematic cross-sectional process views illustratinga flip chip mounting method in Embodiment 3 of the present invention.

FIGS. 8A to 8C are schematic cross-sectional process views illustratinga modified example of the flip chip mounting method in Embodiment 3 ofthe present invention.

FIGS. 9A to 9E are schematic cross-sectional process views illustratinga flip chip mounting method in Embodiment 4 of the present invention.

FIGS. 10A and 10B are main portion enlarged cross-sectional viewsillustrating the flip chip mounting method in Embodiment 4 of thepresent invention.

FIG. 11 is a main portion configuration cross-sectional view of a flipchip mounting apparatus used in each embodiment of the presentinvention.

DESCRIPTION OF THE INVENTION

The present invention relates to a flip chip mounting method in whichconnection terminals of a circuit board are aligned with electrodeterminals of a semiconductor chip while the connection terminals and theelectrode terminals are held in a contact state, or the connectionterminals of the circuit board are aligned with the electrode terminalsof the semiconductor chip while the connection terminals and theelectrode terminals are held with a predetermined gap therebetween; amelted solder resin composition is supplied from at least one end facedirection of the semiconductor chip by a capillary phenomenon; the resinin the solder resin composition is cured; at the time of the supply,melted solder powder in the solder resin composition is moved throughthe predetermined gap across which the circuit board and thesemiconductor chip are held, and the solder powder is self-assembled andgrown, whereby the connection terminals are connected electrically tothe electrode terminals.

In the present invention, a resin component of the solder resincomposition supplied from at least one direction may be discharged froma direction other than the at least one direction.

Furthermore, in the supply step, the solder resin composition suppliedfrom at least one end face direction of the semiconductor chip may besupplied while being moved along the end face.

Furthermore, in the holding step, the circuit board and thesemiconductor chip may be held by aspiration.

Furthermore, in the holding step, a plurality of the semiconductor chipsmay be held.

Furthermore, the semiconductor chip is mounted on an interposer having aplurality of external connection terminals, thereby connecting theconnection terminals of the circuit board electrically to the externalconnection terminals.

These methods enable the mounting at a low load, so that a thin orarea-arranged semiconductor chip, or an insulating material with a lowdielectric constant can be used. Furthermore, the gap between theelectrode terminals of the semiconductor chip and the connectionterminals of the circuit board can be kept at an optimum distance.Therefore, the disconnection, connection with a high resistance, and thelike are unlikely to occur due to the uniform connection between theelectrode terminals and the connection terminals, which can enhance ayield Furthermore, the circuit board and the semiconductor chip can befixed with a resin at a low load simultaneously with the electricalconnection, so that a flip chip mounted body excellent in productivityand reliability can be realized.

Furthermore, a flip chip mounting method of the present invention forplacing a semiconductor chip having a plurality of electrode terminalsso that it is opposed to a circuit board having a plurality toconnection terminals, and connecting the connection terminals of thecircuit board electrically to the electrode terminals of thesemiconductor chip, includes: a holding step of holding the circuitboard and the semiconductor chip; an arrangement step of aligning theconnection terminals of the circuit board with the electrode terminalsof the semiconductor chip while holding the connection terminals and theelectrode terminals in a contact state, or aligning the connectionterminals of the circuit board with the electrode terminals of thesemiconductor chip while holding the connection terminals and theelectrode terminals with a predetermined gap therebetween; a firstheating step of heating at least the circuit board or the semiconductorchip to a temperature at which solder power in a solder resincomposition formed of the solder powder and a first resin is melted; afirst supply step of supplying the solder resin composition to thepredetermined gap across which the circuit board and the semiconductorchip are held, from at least one end face direction of the semiconductorchip by a capillary phenomenon; a connection step of moving the meltedsolder powder in the resin composition through the predetermined gapacross which the circuit board and the semiconductor chip are held, andself-assembling and growing the solder powder to form a solder layer,thereby connecting the connection terminals electrically to theelectrode terminals; a discharging step of discharging a resincomposition other than the solder layer; a second heating step ofheating at least the circuit board or the semiconductor chip to atemperature at which the solder layer is not melted and the second resinis melted; a second supply step of supplying a second resin to thepredetermined gap across which the circuit board and the semiconductorchip are held, from at least one end face direction of the semiconductorchip by a capillary phenomenon; and a curing step of curing the secondresin.

Furthermore, in the first supply step, the solder resin compositionsupplied from at least one direction may be discharged from a directionother than the at least one direction.

Furthermore, the second supply step of supplying the second resin mayinclude a first step of supplying a first insulating resin covering atleast a side surface of the solder layer; and a second step of supplyinga second insulating resin covering the first insulating resin andfilling a predetermined gap between the circuit board and thesemiconductor chip, wherein the second resin is composed of the firstinsulating resin and the second insulating resin

Furthermore, the above-mentioned flip chip mounting method further mayinclude the step of provisionally curing the first insulating resinafter the first step.

Furthermore, the first insulating resin may cover at least a sidesurface of the solder layer due to surface tension.

Furthermore, the first insulating resin may be made of a material havinga modulus of elasticity lower than that of the second insulating resin.

Furthermore, the solder resin composition may be a viscous body.

Furthermore, the viscous body may be made of a resin, a solvent having ahigh boiling point, or oil.

These methods further can decrease the possibility of the solder powderremaining between the solder layers. Therefore, a flip chip mounted bodyexcellent in electrical characteristics such as the enhancement of awithstand voltage and the prevention of a short-circuit, and themechanical characteristics with respect to a stress can be realized.

Furthermore, a flip chip mounting apparatus of the present invention forflip chip mounting a semiconductor chip on a circuit board includes:holding means for holding the circuit board and the semiconductor chip;arrangement means for aligning the connection terminals of the circuitboard with the electrode terminals of the semiconductor chip whileholding the connection terminals and the electrode terminals in acontact state, or aligning the connection terminals of the circuit boardwith the electrode terminals of the semiconductor chip while holding theconnection terminals and the electrode terminals with a predeterminedgap therebetween; heating means for heating at least the circuit boardor the semiconductor chip to a temperature at which solder powder in asolder resin composition made of the solder powder and a resin ismelted; supply means for supplying the solder resin composition to thepredetermined gap across which the circuit board and the semiconductorchip are held, from at least one end face direction of the semiconductorchip by a capillary phenomenon; and curing means for curing the resin inthe solder resin composition.

Furthermore, the supply means may be a dispenser.

Furthermore, the holding means may use aspiration.

Furthermore, the holding means may hold the circuit board and thesemiconductor chip in such a manner that the circuit board and thesemiconductor chip are inclined. Furthermore, the heating means furthermay include cooling means.

Furthermore, the above flip chip mounting apparatus further may includeinspection means for inspecting an electrical connection between thesemiconductor chip and the circuit board.

This apparatus can produce a flip chip mounted body that is excellent inreliability and has low cost and satisfactory productivity.

Furthermore, a flip chip mounted body of the present invention includes:a circuit board having a plurality of connection terminals; asemiconductor chip having a plurality of electrode terminals placed soas to be opposed to the connection terminals; a solder layer thatconnects the connection terminals of the circuit board electrically tothe electrode terminals of the semiconductor chip; and a firstinsulating resin covering at least the solder layer and a secondinsulating resin covering the first insulating resin and fixing thecircuit board and the semiconductor chip to each other.

Furthermore, the first insulating resin may be made of a material havinga modulus of elasticity lower than that of the second insulating resin.

According to this configuration, a flip chip mounted body excellent inreliability of connection and the like and mechanical strength can berealized.

According to the flip chip mounting method and the mounting apparatusthereof according to the present invention, the connection state betweenthe electrode terminals of the semiconductor chip and the connectionterminals of the circuit board can be uniform, so that excellentconnection reliability and high production efficiency can be realized.The flip chip mounting method and the mounting apparatus thereofaccording to the present invention are effective for the connectionbetween boards such as a circuit board and a wiring board, as well asthe connection between flip-chips and interposers.

Arbitrary solder particles can be selected to be used. Examples thereoflisted in Table 1 can be used. Materials listed in Table 1 as examplesmay be used alone or in combination appropriately. Moreover, it ispreferable to use a material whose melting point is lower than a curingtemperature of the thermosetting resin as the solder particles, becausethe resin is heated and cured after the resin flows and isself-assembled, whereby electrical connection and sealing with the resincan be achieved.

TABLE 1 Composition of solder particles Melting point (solidus) (° C.)Sn—58Bi 139 Sn—37Pb 183 Sn—9Zn 199 Sn—3.0Ag—0.5Cu 217 Sn—3.5Ag 221Sn—0.7Cu 228 12Sn—2.0Ag—10Sb—Pb 240

A melting point of the solder particles preferably ranges from 100° C.to 300° C., and more preferably ranges from 139° C. to 240° C., as shownin Table 1. If the melting point is less than 100° C., a problem indurability tends to occur. If the melting point is more than 300° C., itbecomes difficult to select the resin.

An average particle diameter of the solder particles preferably rangesfrom 1 μm to 30 μm, and more preferably ranges from 5 μm to 20 μm. Whenthe average particle diameter is less than 1 μm, it becomes difficult tomelt the solder particles due to the surface oxidation, and theformation of the electric connectors tends to take too much time. Whenthe average particle diameter is more than 30 μm, it becomes difficultto obtain the electric connectors due to the sedimentation of the solderparticles. Note here that the average particle diameter can be measuredusing a commercially available particle size distribution analyzer. Forexample, the average particle diameter can be measured using a laserdiffraction particle size analyzer (LA920) available from HORIBA, Ltd.,a laser diffraction particle size analyzer (SALD2100) available fromShimadzu Corporation, or the like.

Next, the resin will be described. Typical examples of the resininclude: thermosetting resins such as epoxy resin, phenol resin,silicone resin, diallyl phthalate resin, furan resin, and melamineresin; thermoplastic resins such as polyester elastomer, fluororesin,polyimide resin, polyamide resin, and aramid resin; photocurable(ultraviolet curable) resins; and mixtures thereof in combination.

The mixing ratio by weight of the solder particles and the resinpreferably is in the following range: conductive particles:resin=76 to4:24 to 96, more preferably, solder particles:resin=50 to 20:50 to 80.It is preferable to use the solder particles and the resin after theyhave been mixed together homogenously. For example, 30% by weight of thesolder particles and 70% by weight of the epoxy resin are mixedhomogenously by a kneading machine, and the thus-obtained mixture isformed into a paste while the dispersion state of the solder particlesis kept. A preferred viscosity of the paste ranges from 20 to 100 Pa·S(pascal second).

Furthermore, in preferred examples of the present invention, lead-freeSn.3Ag.0.5Cu solder alloy particles whose melting point ranges from 200°C. to 250° C. can be used as the solder particles, for example. When theresin is a thermosetting resin, it is preferable that the curingtemperature of the resin is higher than the melting point of the solder.With this configuration, it is possible to cure the resin during thesteps of forming electric connectors and forming metal bumps, thusallowing the operation process to be shortened.

The basic mechanism of an exemplary flip chip mounting method based onthe concept of the present invention will be described with reference toFIGS. 1A to 1C. First, as shown in FIG. 1A, a solder resin composition15 containing solder powder 12, a convection additive 13, and a resin 14is supplied onto a circuit board 10 on which a plurality of connectionterminals 11 are formed.

Next, as shown in FIG. 1B, the circuit board 10 and a semiconductor chip20 are brought into contact with each other through the interveningsolder resin composition 15 that is supplied between the circuit board10 and the semiconductor chip 20. At this time, the semiconductor chip20 having a plurality of electrode terminals 21 is disposed so as to beopposed to the circuit board 10 having the plurality of the connectionterminals 11. In this state, the circuit board 10 is heated so as tomelt the solder resin composition 15. Here, the circuit board 10 isheated at a temperature higher than a melting point of the solder powder12. The melted solder powder 12 is bound together in the melted resin14, and is self-assembled between the connection terminal 11 and theelectrode terminal 21 that have high wettability so as to form a solderconnector 22, as shown in FIG. 1C.

Then, the resin 14 is cured, whereby the semiconductor chip 20 is fixedto the circuit board 10.

This method is characterized in that the solder resin composition 15containing the solder powder 12 further contains the convection additive13 that is boiled at a temperature at which the solder powder 12 ismelted. That is, at the temperature at which the solder powder 12 ismelted, the convection additive 13 contained in the solder resincomposition 15 is boiled. Then, the convection of the boiled convectionadditive 13 occurs in the resin 14, thereby promoting the transfer ofthe melted solder powder 12 that flows in the resin 14. As a result, themelted solder powder that has been grown uniformly is self-assembledbetween the connection terminal 11 of the circuit board 10 and theelectrode terminal 21 of the semiconductor chip 20 that have highwettability, whereby the connection terminal 11 and the electrodeterminal 21 are connected electrically via the uniform and fine solderconnector 22.

That is, the above-described method is intended to add means fortransferring the melted solder powder forcefully by allowing the solderresin composition containing the solder powder further to contain theconvection additive. Incidentally, the convection additive may be asolvent that is boiled or evaporated by heat, and hardly remains in theresin after the completion of the steps.

In the light of the similar technical standpoint, the present inventionhas realized a novel flip chip mounting method and flip chip mountingapparatus with high reliability by supplying and transferring meltedsolder powder through a capillary phenomenon without using a convectionadditive. Furthermore, according to the embodiments of the presentinvention, a flip chip mounted body having high productivity andexcellent reliability can be realized.

Hereinafter the embodiments of the present invention will be describedin detail with reference to the drawings The drawings are shown underthe condition of being magnified arbitrarily for ease of understanding.

EMBODIMENT 1

Hereinafter, a flip chip mounting method in Embodiment 1 of the presentinvention will be described with reference to FIGS. 2A-2E. FIGS. 2A-2Eare schematic cross-sectional process views illustrating the flip chipmounting method in Embodiment 1 of the present invention. First, asshown in FIG. 2A, a semiconductor chip 206 having a plurality ofelectrode terminals 207 is held by a pickup jig 201. The semiconductorchip 206 is aspirated to be held by vacuum suction, for example, via asuction path 203 formed of small holes and a suction pipe 202 providedin the pickup jig 201.

Next, as shown in FIG. 2B, the pickup jig 201 holding the semiconductorchip 206 is placed, for example, on a circuit board 213, which has aplurality of connection terminals 211, held by a holding platform 204such as a table by aspiration or the like. In the arrangement, theelectrode terminals 207 of the semiconductor chip 206 and the connectionterminals 211 of the circuit board 213 are aligned so as to be opposedto each other, for example, with an image recognition apparatus such asa camera. The circuit board 213 also can be fixed with its positionregulated, by being accommodated in a concave portion (not shown)provided in the holding platform 204.

Then, under the condition that the semiconductor chip 206 and thecircuit board 213 are aligned, the holding platform 204 or the pickupjig 201 is moved to a position where a predetermined spacing is providedbetween the electrode terminals 207 of the semiconductor chip 206 andthe connection terminals 211 of the circuit board 213. In this case, thepredetermined spacing is provided to such a degree that a solder resincomposition described below can enter by a capillary phenomenon, and theelectrode terminals 207 and the connection terminals 211 do not contacteach other and melted solder powder can enter therebetween For example,the distance between the electrode terminals 207 of the semiconductorchip 206 and the connection terminals 211 of the circuit board 213 isadjusted to be about 10 μm to 50 μm, considering, for example, thethickness of the semiconductor chip 206, etc.

Furthermore, the semiconductor chip 206 or the circuit board 213 isheated, for example, to a temperature (150° C. to 250° C.) at whichsolder powder is melted with a heating apparatus such as an externalheater (not shown) or a heater (not shown) incorporated in the pickupjig 201 or the holding platform 204.

Next, as shown in FIG. 2C, a solder resin composition 216 containingsolder powder 214 and a resin 215 is supplied to a gap 218 having apredetermined size from at least one end face direction of thesemiconductor chip 206, using a coating apparatus 217 such as adispenser, by a capillary phenomenon. At this time, while the solderresin composition 216 supplied to the gap 218 is flowing through the gap218, at least a resin component is discharged from an opposite direction(represented by an open arrow). Herein, as the solder powder, forexample, Sn—Ag based solder powder is used.

In the step in which a solder resin component is discharged while thesolder resin composition 216 is supplied and flows, the solder powder214 contained in the solder resin composition 216 is melted by heating.Then, the melted solder powder 214 is self-assembled and grows betweenthe connection terminals 211 of the circuit board 213 and the electrodeterminals 207 of the semiconductor chip 206, whereby solder layers 219connecting the connection terminals 211 electrically to the electrodeterminals 207 are formed. More specifically, along with the flow of thesolder resin composition 216, the melted solder powder 214 flowing inthe solder resin composition 216 is self-assembled selectively on theconnection terminals 211 and the electrode terminals 207 having highwettability, whereby the solder layers 219 are formed finally betweenthe connection terminals 211 and the electrode terminals 207.

It is considered that the bonding of the melted solder powder 214 andthe self-assembly thereof on the connection terminals 211 and theelectrode terminals 207 proceed extremely locally in a short period oftime in the solder resin composition 216. Therefore, in order to allowthe self-assembly to proceed uniformly over an entire region of thesemiconductor chip 206 and the uniform solder layers 219 withoutvariations to be formed, it is necessary to use means for moving themelted solder powder 214 floating in the solder resin composition 216forcefully.

According to Embodiment 1 of the present invention, the heated solderresin composition 216 supplied to the gap 218 by a capillary phenomenonflows through the gap 218 and a resin component is discharged outside.During this step, the melted solder powder 214 has a functional effectsimilar to the forceful movement in the solder resin composition 216supplied to the gap 218. That is, the melted solder powder brings abouta functional effect similar to the promotion of the movement of themelted solder powder by the convection additive shown in FIGS. 1A-1C

Next, as shown in FIG. 2D, as the solder resin composition 216 flowsthrough the gap 218, the solder layers 219 are formed successivelybetween the electrode terminals 207 and the connection terminals 211.Then, after the solder layers 219 are formed, in the case where theresin 215 in the solder resin composition 216 supplied to the gap 218is, for example, a thermoplastic resin, the resin 215 is cured by, forexample, water circulation, forceful cooling by a cooling apparatus (notshown) such as a Peltier element incorporated in the pickup jig 201 orthe holding platform 204, or natural cooling. Consequently, theelectrode terminals 207 of the semiconductor chip 206 and the connectionterminals 211 of the circuit board 213 are connected electrically by thesolder layers 219, and simultaneously they adhere to or are fixed toeach other with the resin 215 in a similar manner to that of anunderfill. In the case where the resin 215 in the solder resincomposition 216 is, for example, a thermosetting resin, the abovecooling may be conducted after the pickup jig 201 or the holdingplatform 204 is heated once to a temperature for curing the resin 215 orhigher to cure the resin 215. At this time, in the case where the resin215 is cured to shrink, it is preferred to set the gap 218 to be narrowto such a degree that the resin 215 is cured to shrink. This can preventthe decrease in adhesive strength caused by the peeling between theresin 215 and the semiconductor chip 206.

Then, as shown in FIG. 2E, the resultant stack is removed from thepickup jig 201, whereby a flip chip mounted body 200 in which thesemiconductor chip 206 is flip-chip mounted on the circuit board 213 canbe produced.

A specific example will be described. In FIG. 2B, the spacing betweenthe electrode terminals 207 of the semiconductor chip 206 and theconnection terminals 211 of the fiberglass-reinforced epoxy impregnatedresin circuit board 213 was adjusted to be 20 μm. In this state, asolder resin paste (heated to 250° C.), in which 70 parts by weight of abisphenol F epoxy resin (Epicoat 806 manufactured by Japan Epoxy ResinCo., Ltd.) and 30 parts by weight of Sn.3Ag.0.5Cu powder (melting point:217° C.) having an average particle size of 12 μm were mixed uniformly,was allowed to enter between the circuit board and the surface of thesemiconductor chip from one direction by a capillary phenomenon, using adispenser, as shown in FIGS. 2C-2D, and discharged in the otherdirection. The heating temperature at this time was 250° C. After that,the temperature was cooled to room temperature, and the cross-sectionwas observed to confirm the state in FIG. 2E.

According to Embodiment 1 of the present invention, the electrodeterminals of the semiconductor chip and the connection terminals of thecircuit board are connected more precisely by the uniform solder layersformed by the self-assembly of the melted solder powder supplied by acapillary phenomenon.

Furthermore, the resin filling the gap between the circuit board and thesemiconductor chip is cured, whereby the semiconductor chip can be fixedto the circuit board.

Thus, the electrical connection between the electrode terminals of thesemiconductor chip and the connection terminals of the circuit board,and the fixing of the semiconductor chip to the circuit board can beperformed simultaneously, so that a flip chip mounted body that isexcellent in reliability and has high productivity can be produced.

Furthermore, the solder resin composition is supplied using a capillaryphenomenon and allowed to flow in the gap. Therefore, the solder resincomposition may not contain a convection additive. As a result, theselection range of the solder resin composition can be broadened.

Furthermore, the solder layers are formed by the self-assembly of themelted solder powder flowing in the solder resin composition between theelectrode terminals of the semiconductor chip and the connectionterminals of the circuit board held at a predetermined spacing.Therefore, the load applied to the semiconductor chip and the circuitboard can be decreased. Consequently, a highly reliable flip chipmounted body, which prevents the deformation due to the load duringmounting, can be realized even with respect to a thinned semiconductorchip.

In Embodiment 1 of the present invention, as the solder resincomposition, it is preferred to use a resin which is in a liquid form orwhose viscosity is decreased at a temperature at which the solder powderis melted. For example, as a thermosetting resin that is in a liquidform at a temperature at which the solder powder is melted, epoxy resin,polyimide resin, polyphenylene ether resin, phenol resin, fluorineresin, isocyanate resin, or the like can be used. Furthermore, as athermoplastic resin whose viscosity is decreased at a temperature atwhich the solder powder is melted, wholly aromatic polyester, fluorineresin, polyphenylene oxide resin, syndiotactic polystyrene resin,polyimide resin, polyamide resin, aramid resin, polyphenylene sulfideresin, or the like can be used.

Furthermore, the supply of the solder resin composition is not limitedto the method of Embodiment 1 of the present invention shown in FIG. 3A.For example, as shown in FIG. 3B, the solder resin composition may besupplied while moving in one end face direction of the semiconductorchip 206. Furthermore, as shown in FIG. 4A, the solder resin compositionmay be supplied while moving on end faces in two directions of thesemiconductor chip 206, or as shown in FIG. 4B, the solder resincomposition 216 may be supplied from each end face in three directionsof the semiconductor chip 206. Consequently, the solder resincomposition 216 can be supplied to the gap uniformly, and it is possibleto decrease the possibility of a region without the solder resincomposition being formed in the gap between the semiconductor chip andthe circuit board due to air bubbles or the like.

In the case where a plurality of semiconductor chips 206 are flip chipmounted on the circuit board 213 simultaneously by the supply methodsshown in FIGS. 4 and 5, the effect thereof is great because theproduction time and production cost of a flip chip mounted body can bereduced remarkably.

Furthermore, according to Embodiment 1 of the present invention, thesemiconductor chip also can be applied to, for example, flip chipmounting of a compound semiconductor such as a semiconductor chip madeof silicon-germanium or gallium-arsenic, as well as the semiconductorchip made of silicon. That is, a thin semiconductor chip made of siliconor a semiconductor chip made of a compound with weak mechanical strengthcan be flip chip mounted at a small load, so that a highly reliable flipchip mounted body can be realized.

Furthermore, an example has been illustrated in which the electrodeterminals 207 of the semiconductor chip 206 and the connection terminals211 of the circuit board 213 are set to have a predetermined spacingunder the condition that the semiconductor chip 206 and the circuitboard 213 are aligned as shown in FIG. 2B. However, the electrodeterminals 207 of the semiconductor chip 206 and the connection terminals211 of the circuit board 213 may be brought into contact with each otherunder the condition that the semiconductor chip 206 and the circuitboard 213 are aligned for the following reason. The connection terminalsof the circuit board 213 are formed as projections with respect to theboard surface, whereas the electrodes on the semiconductor chip 206 aresubstantially flat. Thus, a gap corresponding to the thickness of theconnection terminals of the circuit board is formed between thesemiconductor chip 206 and the circuit board 213 even if a predeterminedspacing is not formed. This is because a resin can be self-assembled onthe periphery of the electrode terminals 207 of the semiconductor chip206 and the connection terminals 211 of the circuit board 213 via thegap.

Although Embodiment 1 of the present invention has been described withreference to the views in which the pickup jig and the holding platformare placed horizontally, the present invention is not limited thereto.For example, the pickup jig and the holding platform may be placed so asto be inclined in such a manner that the end face direction in which thesolder resin composition is supplied by a capillary phenomenon is set tobe high. Consequently, the solder resin composition is not only suppliedby a capillary phenomenon but also is dropped along the inclination dueto the self-weight of the solder resin composition, whereby the supplyspeed can be enhanced. This can enhance the flowability of the solderresin composition in the gap to enable flip chip mounting in a shortperiod of time. A resin component of the solder resin composition alsocan be discharged in a short period of time. Therefore, flip chipmounting excellent in productivity can be realized.

EMBODIMENT 2

Hereinafter, a flip chip mounting method in Embodiment 2 of the presentinvention will be described with reference to FIGS. 5A-5E. FIGS. 5A-5Eare schematic cross-sectional process views illustrating the flip chipmounting method in Embodiment 2 of the present invention. Embodiment 2of the present invention is different from Embodiment 1 in that asemiconductor chip is flip-chip mounted on a circuit board while beingmounted on an interposer. In FIGS. 5A-5E, the same constituent elementsas those in FIGS. 2A-2E are denoted with the same reference numerals asthose therein.

First, as shown in FIG. 5A, a semiconductor chip 206 mounted at least onan interposer 301 is held by a pickup jig 201. Herein, the semiconductorchip 206 is mounted on the interposer 301 by a flip chip mountingmethod, a wire bonding method, or the like. A plurality of electrodeterminals (not shown) of the semiconductor chip 206 are connectedelectrically to a plurality of external connection terminals 302 formedon the surface of the interposer 301. Then, the interposer 301 is heldby vacuum aspiration, for example, via a suction path 203 formed ofsmall holes and a suction pipe 202 provided in the pickup jig 201.

Next, as shown in FIG. 5B, the pickup jig 201 holding the interposer 301with the semiconductor chip 206 mounted thereon is placed on the circuitboard 213 having the plurality of connection terminals 211 held, forexample, by a holding platform 204 such as a table by aspiration or thelike. In the arrangement, the external connection terminals 302 of theinterposer 301 and the connection terminals 211 of the circuit board 213are aligned so as to be opposed to each other, for example, with animage recognition apparatus such as a camera. The circuit board 213 alsomay be fixed with its position regulated, by being accommodated in aconcave portion (not shown) provided in the holding platform 204.

Then, under the condition that the interposer 301 and the circuit board213 are aligned, the holding platform 204 or the pickup jig 201 is movedto a position where a predetermined spacing is provided between theexternal connection terminals 302 of the interposer 301 and theconnection terminals 211 of the circuit board 213. In this case, thepredetermined spacing is provided so that a solder resin compositiondescribed below can enter by a capillary phenomenon, and the externalconnection terminals 302 and the connection terminals 211 do not contacteach other and melted solder power can enter therebetween. For example,the predetermined spacing is about 30 μm to 300 μm.

Furthermore, the interposer 301 or the circuit board 213 is heated viathe semiconductor chip 206, for example, to a temperature (150° C. to250° C.) at which solder powder is melted with a heating apparatus suchas an external heater (not shown) or a heater (not shown) incorporatedin the pickup jig 201 or the holding platform 204.

Next, as shown in FIG. 5C, a solder resin composition 216 containingsolder powder 214 and a resin 215 is supplied to a gap 218 having apredetermined size from at least one end face direction of theinterposer 301, using a coating apparatus 217 such as a dispenser, by acapillary phenomenon. At this time, while the solder resin composition216 supplied to the gap 218 is flowing through the gap 218, at least aresin component is discharged from a direction (represented by an openarrow) opposite to the direction in which the solder resin compositionis supplied. Herein, as the solder powder, for example, Sn—Ag basedsolder powder is used.

In the step in which a solder component is discharged while the solderresin composition 216 is supplied and flows, the solder powder 214contained in the solder resin composition 216 is melted by heating.Then, the melted solder powder 214 is self-assembled and grows betweenthe connection terminals 211 of the circuit board 213 and the externalconnection terminals 302 of the interposer 301, whereby solder layers219 connecting the connection terminals 211 electrically to the externalconnection terminals 302 are formed. More specifically along with theflow of the solder resin composition 216, the melted solder powder 214floating in the solder resin composition 216 is self-assembledselectively on the connection terminals 211 and the external connectionterminals 302 having high wettability, whereby the solder layers 219 areformed finally between the connection terminals 211 and the externalconnection terminals 302.

Next, as shown in FIG. 5D, as the solder resin composition 216 flowsthrough the gap 218, the solder layers 219 are formed successivelybetween the external connection terminals 302 and the connectionterminals 211. Then, after the solder layers 219 are formed, forexample, the resin 215 made of a thermoplastic resin in the solder resincomposition 216 supplied to the gap 218 is cured by, for example, watercirculation, forceful cooling by a cooling apparatus (not shown) such asa Peltier element incorporated in the pickup jig 201 or the holdingplatform 204, or natural cooling. Consequently, the external connectionterminals 302 of the interposer 301 and the connection terminals 211 ofthe circuit board 213 are connected electrically by the solder layers219, and simultaneously, they adhere to or are fixed to each other withthe resin 215 in a similar manner to that of an underfill. In the casewhere the resin 215 in the solder resin composition 216 is, for example,a thermosetting resin, the pickup jig 201 or the holding platform 204may be cured by being once heated to a temperature for curing the resin215 or higher. At this time, in the case where the resin 215 is cured toshrink, it is preferred to set the gap 218 to be narrow to such a degreethat the resin 215 is cured to shrink. This can prevent the decrease inadhesive strength caused by the peeling between the resin 215 and thesemiconductor chip 206.

Then, as shown in FIG. 5E, the resultant stack is removed from thepickup jig 201, whereby a flip chip mounted body 300 in which theinterposer 301 with the semiconductor chip 206 mounted thereon isflip-chip mounted on the circuit board 213 can be produced.

According to Embodiment 2 of the present invention, the effects similarto those in Embodiment 1 are obtained.

EMBODIMENT 3

Hereinafter, a flip chip mounting method in Embodiment 3 of the presentinvention will be described with reference to FIGS. 6A-6E and FIGS.7A-7E. FIG. 6A-6E and FIGS. 7A-7E are schematic cross-sectional processviews illustrating the flip chip mounting method in Embodiment 3 of thepresent invention. In FIGS. 6A-6E and FIGS. 7A-7E, the same constituentelements as those in FIGS. 2A-2E are denoted with the same referencenumerals as those therein.

First, as shown in FIG. 6A, a semiconductor chip 206 having a pluralityof electrode terminals 207 is held by a pickup jig 201. Thesemiconductor chip 206 is held by vacuum suction, for example, via asuction path 203 formed of small holes and a suction pipe 202 providedin the pickup jig 201.

Next, as shown in FIG. 6B, the pickup jig 201 holding the semiconductorchip 206 is placed, for example, on a circuit board 213, which has aplurality of connection terminals 211, held by a holding platform 204such as a table by aspiration or the like. In the arrangement, theelectrode terminals 207 of the semiconductor chip 206 and the connectionterminals 211 of the circuit board 213 are aligned so as to be opposedto each other, for example, with an image recognition apparatus such asa camera. The circuit board 213 also can be fixed with its positionregulated, by being accommodated in a concave portion (not shown)provided in the holding platform 204.

Then, under the condition that the semiconductor chip 206 and thecircuit board 213 are aligned, the holding platform 204 or the pickupjig 201 is moved to a position where a predetermined spacing is providedbetween the electrode terminals 207 of the semiconductor chip 206 andthe connection terminals 211 of the circuit board 213. In this case, thepredetermined spacing is provided so that a solder resin compositiondescribed below can enter by a capillary phenomenon, and the electrodeterminals 207 and the connection terminals 211 do not contact each otherand melted solder power can enter therebetween. For example, thepredetermined spacing is about 30 μm to 300 μm.

Furthermore, the semiconductor chip 206 or the circuit board 213 isheated, for example, to a temperature (150° to 250° C.) at which solderpowder is melted with a heating apparatus such as an external heater(not shown) or a heater (not shown) incorporated in the pickup jig 201or the holding platform 204.

Next, as shown in FIG. 6C, a solder resin composition 402 containingsolder powder 214 and a first resin 401 is supplied to a gap 218 havinga predetermined size from at least one end face direction of thesemiconductor chip 206, using a coating apparatus 217 such as adispenser, by a capillary phenomenon. At this time, while the solderresin composition 402 supplied to the gap 218 flows through the gap 218,a resin component is discharged from a direction (represented by an openarrow) opposite to the direction in which the solder resin composition402 is supplied. Herein, as the solder powder, for example, Sn—Ag basedsolder powder is used.

In the step in which a solder resin component is discharged while thesolder resin composition 402 is supplied and flows, the solder powder214 contained in the solder resin composition 402 is melted by heating.Then, the melted solder powder 214 is self-assembled and grows betweenthe connection terminals 211 of the circuit board 213 and the electrodeterminals 207 of the semiconductor chip 206, whereby solder layers 219connecting the connection terminals 211 electrically to the electrodeterminals 207 are formed. More specifically, the melted solder powder214 floating in the solder resin composition 402 is self-assembledselectively on the connection terminals 211 or the electrode terminals207 having high wettability, whereby the solder layers 219 are formedfinally between the connection terminals 211 and the electrode terminals207.

Next, as shown in FIG. 6D, as the solder resin composition 402 flowsthrough the gap 218, the solder layers 219 are formed successivelybetween the electrode terminals 207 and the connection terminals 211.Then, as shown in FIG. 6E, the uniform solder layers 219 withoutvariations are formed over an entire region between the electrodeterminals 207 of the semiconductor chip 206 and the connection terminals211 of the circuit board 213. At this time, the gap 218 is filled withthe first resin 401 in an uncured state. Reference numeral 400 denotes aflip chip mounted body thus obtained.

The above steps are the same as those in Embodiment 1 and the followingsteps are different from those in Embodiment 1.

Next, as shown in FIG. 7A, the first resin 401 filling the gap 218 isdischarged. Herein, the first resin 401 can be discharged, for example,by injecting inactive gas or air from a nozzle 403 and using thepressure of the injected gas. Furthermore, along with the injection ofgas or the like, the first resin 401 may be discharged by aspirationwith a suction pipe 404 under a reduced pressure. The discharge of thefirst resin 401 by the injection of gas and the discharge of the firstresin 401 by the aspiration with the suction pipe 404 may be performedsimultaneously. When the first resin 401 is discharged, in order toprevent the shape and the like of the solder layers 219 from beingdeformed due to the pressure of gas or the aspiration under a reducedpressure, it is preferred to set the temperatures of the pickup jig 201and the holding platform 204 to be the curing temperature of the solderlayers 219 or lower and to be the melting temperature of the first resin401 or higher, thereby solidifying the solder layers 219. Consequently,as shown in FIG. 7B, the semiconductor chip 206 and the circuit board213 are bonded to each other only with the solder layers 219.

Next, as shown in FIG. 7C, after the first resin 401 is discharged fromthe gap 218, a second resin 405 is supplied to the gap 218 having apredetermined size from at least one end face direction of thesemiconductor chip 206 by a capillary phenomenon, using a coatingapparatus 217 such as a dispenser.

As a result, as shown in FIG. 7D, the gap between the semiconductor chip206 and the circuit board 213 is filled again with the second resin 405.The semiconductor chip 206 is allowed to adhere to the circuit board 213by curing the second resin 405. Herein, the second resin 405 can becured, for example, by heating the pickup jig 201 or the holdingplatform 204 to a temperature at which the second resin 405 is cured orhigher, if the second resin 405 is a thermosetting resin.

Next, as shown in FIG. 7E, the resultant stack is removed from thepickup jig 201 and the holding platform 204, whereby a flip chip mountedbody 400 in which the semiconductor chip 206 is flip-chip mounted on thecircuit board 213 is completed.

According to the method of Embodiment 3 of the present invention, bychanging the material for the first resin 401 used in the step offorming the solder layers 219 connecting the connection terminals 211 ofthe circuit board 213 to the electrode terminals 207 of thesemiconductor chip 206, and the material for the second resin 405 usedin the step of allowing the semiconductor chip 206 to adhere to thecircuit board 213, a highly reliable flip chip mounted body 400 can beproduced.

More specifically as the first resin 401, a resin having viscositysuitable for keeping the flowability of the melted solder powder 214 canbe used in the connection step of forming the solder layers 218.Furthermore, as the second resin 405, a resin, to which an inorganicfiller that not only functions as an underfill but also alleviates athermal expansion difference is added for example, can be used in thecuring step of allowing the semiconductor chip 206 to adhere to thecircuit board 213. Then, by selecting these resins independently in anoptimum combination, the electrical connection and mechanical adhesionof the semiconductor chip 206 to the circuit board 213 can be performedmore exactly.

The first resin 401 is not required to be curable. Therefore, the firstresin 401 is not limited to a resin material such as a thermosettingresin and a thermoplastic resin illustrated in Embodiment 1, and aviscous body having appropriate viscosity can be used.

Furthermore, as a material for the viscous body, a solvent having a highboiling point, oil, or the like can be used, which is not boiled at atemperature at which solder powder is melted.

For example, as the solvent having a high boiling point, butyl carbitol,butyl carbitol acetate, or the like can be used, and as the oil,silicone oil or the like can be used. Although the viscosity of theseviscous bodies is not particularly limited, 10 Pa·s or less is preferredas the viscosity at which the melted solder power is likely to move andcan be supplied to the gap 218 between the semiconductor chip 206 andthe circuit board 213 by a capillary phenomenon.

Furthermore, according to the method of Embodiment 3 of the presentinvention, even if a small amount of the melted solder powder 214remains in the first resin 401 without being self-assembled, when thesolder layers 219 are formed, the first resin 401 in which the solderpowder 214 remains is discharged from the gap 218 after the solderlayers 219 are formed. Therefore, the leakage between the solder layers219, the decrease in a withstand voltage, and the like can be avoided

Hereinafter, an application example of the flip chip mounting method inEmbodiment 3 of the present invention will be described with referenceto FIGS. 8A-8C. The application example is similar to the above examplein the steps shown in FIGS. 6A-6E illustrated in Embodiment 3 and isdifferent from the above example in the steps shown in FIGS. 7A-7E. Thatis, the steps in FIGS. 7A-7E are replaced by those shown in FIGS. 8A-8C.

FIGS. 8A-8C are schematic cross-sectional process views illustrating amodified example of the flip chip mounting method in Embodiment 3 of thepresent invention.

First, as shown in FIG. 8A, the gap 218 is fled with the solder resincomposition 402, whereby the solder layers 219 are formed. After that,the second resin 405 is supplied to the gap 218 having a predeterminedsize from at least one end face direction of the semiconductor chip 206by a capillary phenomenon, using the coating apparatus 217 such as adispenser. At this time, the solder powder 214 and the first resin 401remaining in the solder resin composition 402 are discharged as a resultof the supply of the second resin 405.

Then, as shown in FIG. 8B, the gap 218 between the semiconductor chip206 and the circuit board 213 is filled again with the second resin 405.Then, the semiconductor chip 206 is allowed to adhere to the circuitboard 213 by curing the second resin 405. Herein, the second resin 405is cured, for example, by heating the pickup jig 201 or the holdingplatform 204 to a temperature at which the second resin 405 is cured orhigher, if the second resin 405 is a thermosetting resin.

Next, as shown in FIG. 8C, the resultant stack is removed from thepickup jig 201 and the holding platform 204, whereby a flip chip mountedbody 500 in which the semiconductor chip 206 is flip-chip mounted on thecircuit board 213 is completed.

This method enables effects similar to those in Embodiment 3 to beobtained, and simplifies the steps, so that the productivity can beenhanced further

EMBODIMENT 4

Hereinafter, a flip chip mounting method and a flip chip mounted body inEmbodiment 4 of the present invention will be described with referenceto FIGS. 9A-9E and FIGS. 10A-10B. Embodiment 4 is similar to Embodiment3 in the illustrated steps up to FIG. 7B, and different from Embodiment3 in the subsequent steps.

Embodiment 4 of the present invention has a configuration in which theelectrical characteristics such as a withstand voltage between thesolder layers of the flip chip mounted body of Embodiment 3 are enhancedfurther, and will be described below in detail.

FIGS. 9A-9E are schematic cross-sectional process views illustrating theflip chip mounting method in Embodiment 4 of the present invention, andFIGS. 10A-10B are main portion enlarged cross-sectional views showingthe main steps in FIGS. 9A-9E in an enlarged state.

First, FIG. 9A is a view showing a state in which the solder resincomposition containing the melted solder powder and the first resin issupplied to the gap 218 to form the solder layers 219, and the resin isdischarged from the gap 218, in the same way as shown in FIG. 7B ofEmbodiment 3.

Next, as shown in FIG. 9B, the resin other than the solder layers 219 isdischarged from the gap, and thereafter, a first insulating resin 501 issupplied to the gap having a predetermined size from at least one endface direction of the semiconductor chip 206 by a capillary phenomenon,using the coating apparatus 217 such as a dispenser.

Herein, as the first insulating resin 501, for example, a thermosettingresin with a low modulus of elasticity such as a mixture of epoxy resinand flexible epoxy resin can be used. Then, the first insulating resin501 is characterized by a low modulus of elasticity, so that it ispreferred that the first insulating resin 501 does not contain aninorganic filer contained in a resin generally used as an underfill.

The first insulating resin 501 supplied to the gap does not necessarilyfill the gap completely, and may be supplied so as to come into contactwith at least side surfaces of the solder layers 219 when it flowsthrough the gap to be discharged.

Next, as shown in FIG. 9C, furthermore, the first insulating resinfilling the gap 218 is discharged. Herein, the first insulating resincan be discharged, for example, by injecting inactive gas and air from anozzle, and using the pressure of the injected gas, as shown in FIG. 7Aof Embodiment 3.

Consequently, as shown in FIG. 10A, the side surfaces of the solderlayers 219 are covered with the first insulating resin 501. It isconsidered that the side surfaces of the solder layers 219 are coveredwith the first insulating resin 501 due to surface tension.

The surfaces of the semiconductor chip 206 and the circuit board 213other than the side surfaces of the solder layers 219 may be coveredwith the first insulating resin 501.

Next, as shown in FIG. 9D, the second insulating resin 502 is suppliedto the gap having a predetermined size from at least one end facedirection of the semiconductor chip 206 by a capillary phenomenon, usingthe coating apparatus 217 such as a dispenser.

Herein, as the second insulating resin 502, for example, a resin havinga high withstand voltage containing an inorganic filler, which allowsthe semiconductor chip 206 to adhere to the circuit board 213 as anunderfill, can be used. At this time, as shown in FIG. 10B, the secondinsulating resin 502 fills the gap 219 so as to cover the firstinsulating resin 501. That is, the second resin in Embodiment 3 iscomposed of the first insulating resin 501 and the second insulatingresin 502.

When the second insulating resin 502 is supplied, it is preferred thatthe first insulating resin 501 is provisionally cured after beingsupplied so as to prevent the first insulating resin 501 covering theside surfaces of the solder layers 219 from being melted to come off.Provisional curing can be performed by heating, for example, the pickupjig 201 or the holding platform 204.

As shown in FIG. 9E, the electrode terminals 207 of the semiconductorchip 206 and the connection terminals 211 of the circuit board 213 areconnected electrically via the solder layers 219, and the solder layers219 are covered with the first insulating resin 501. Furthermore, thesemiconductor chip 206 and the circuit board 213 are allowed to adhereto each other with the second insulating resin 502, whereby a flip chipmounted body 600 is produced.

In general, when an inorganic filler or the like is added as anunderfill, the thermal expansion coefficient of the semiconductor chip206 is matched with that of the circuit board 213, and the modulus ofelasticity and curing shrinkage are increased, whereby the adhesionbetween the electrode terminals 207 of the semiconductor chip 206 andthe connection terminals 211 of the circuit board 213 is ensured.

However, for example, when a temperature cycle and the like are added soas to have high modulus of elasticity and high shrinkage, a stress isconcentrated on the electrode terminals 207 of the semiconductor chip206 and the connection terminals 211 of the circuit board 213, wherebythe reliability is degraded more due to peeling.

According to Embodiment 4 of the present invention, the solder layersare covered with the second insulating resin (corresponding to theunderfill) via the first insulating resin having a low modulus ofelasticity, so that the stress caused by the second insulating resin canbe alleviated with the first insulating resin. This prevents thedecrease in a withstand voltage between the solder layers, andalleviates the stress occurring due to the temperature cycle or thelike, so that a flip chip mounted body excellent in electricalcharacteristics and reliability can be realized.

Although the present invention has been described using each embodiment,such a description does not limit the present invention and can bemodified variously, and each embodiment can be applied to each other.

In the embodiments of the present invention, although solder powder hasbeen described using Sn—Ag based solder the solder powder is not limitedthereto. The solder powder may be, for example, Sn—Zn based or Sn—Bibased solder free of Pb.

Furthermore, the flip chip mounting apparatus used in each embodiment ofthe present invention will be described with reference to FIG. 11.

FIG. 11 is a main portion configuration cross-sectional view of a flipchip mounting apparatus used in each embodiment of the presentinvention.

As shown in FIG. 11, the flip chip mounting apparatus includes thepickup jig 201 holding a semiconductor chip and the holding platform 204holding a circuit board as main constituent elements. Then, the pickupjig 201 and the holding platform 204 have a suction pipe 202 foraspiration for holding a semiconductor chip and a circuit board, and aheating apparatus 700 such as a heater for heating.

The heating apparatus also may be provided outside. The flip chipmounting apparatus further has a coating apparatus 217 such as adispenser supplying a solder resin composition. Although not shown, forthe purpose of aligning a semiconductor chip with a circuit board, theflip chip mounting apparatus includes a movement device capable ofaligning three-dimensionally and placing the pickup jig 201 and theholding platform 204 based on an image recognition apparatus such as acamera and information thereof. The detailed description of eachapparatus will be omitted since it has been shown in the embodiments.

Furthermore, a detection device such as a probe that is connected to thecircuit board to inspect electrical characteristics may be mounted onthe above flip chip mounting apparatus. Because of this, the flip chipmounting can be inspected while the connection state between thesemiconductor chip and the circuit board via the solder layers is beingmonitored. Consequently, a flip chip mounted body having high yield andbeing excellent in reliability can be produced.

INDUSTRIAL APPLICABILITY

The present invention is applicable to flip chip mounting of anext-generation semiconductor chip whose pitch is being narrowed, and isuseful in the field that desires flip chip mounting excellent inproductivity and reliability.

1. A flip chip mounting method for placing a semiconductor chip having aplurality of electrode terminals so that it is opposed to a circuitboard having a plurality to connection terminals, and connecting theconnection terminals of the circuit board electrically to the electrodeterminals of the semiconductor chip, the method comprising: a holdingstep of holding the circuit board and the semiconductor chip; anarrangement step of aligning the connection terminals of the circuitboard with the electrode terminals of the semiconductor chip whileholding the connection terminals and the electrode terminals in acontact state, or aligning the connection terminals of the circuit boardwith the electrode terminals of the semiconductor chip while holding theconnection terminals and the electrode terminals with a predeterminedgap therebetween; a heating step of heating at least the circuit boardor the semiconductor chip to a temperature at which solder powder in asolder resin composition formed of the solder powder and a resin ismelted; a supply step of supplying the solder resin composition to thepredetermined gap across which the circuit board and the semiconductorchip are held, from at least one end face direction of the semiconductorchip by a capillary phenomenon; and curing the resin in the solder resincomposition, wherein in the supply step of the solder resin composition,the melted solder powder in the solder resin composition is movedthrough the predetermined gap across which the circuit board and thesemiconductor chip are held, and the solder powder is self-assembled andgrown, thereby connecting the connection terminals electrically to theelectrode terminals.
 2. The flip chip mounting method according to claim1, wherein in the supply step, a resin component of the solder resincomposition supplied from at least one direction is discharged from adirection other than the at least one direction.
 3. The flip chipmounting method according to claim 1, wherein in the supply step, thesolder resin composition supplied from at least one end face directionof the semiconductor chip is supplied while being moved along the endface.
 4. The flip chip mounting method according to claim 1, wherein inthe holding step, the circuit board and the semiconductor chip are heldby aspiration.
 5. The flip chip mounting method according to claim 1,wherein in the holding step, a plurality of the semiconductor chips areheld simultaneously.
 6. The flip chip mounting method according to claim1, wherein the semiconductor chip is mounted on an interposer having aplurality of connection terminals, and the interposer with thesemiconductor chip mounted thereon is connected electrically to thecircuit board.
 7. The flip chip mounting method according to claim 1,comprising: after connecting the connection terminals electrically tothe electrode terminals with the solder resin composition, furtherdischarging a resin component other than the solder layer; heating atleast the circuit board or the semiconductor chip to a temperature atwhich the solder layer is not melted and the second resin is melted;supplying the second resin to the predetermined gap across which thecircuit board and the semiconductor chip are held, from at least one endface direction of the semiconductor chip by a capillary phenomenon; andcuring the second resin.
 8. The flip chip mounting method according toclaim 7, wherein the resin component of the solder resin composition isdischarged from the other direction.
 9. The flip chip mounting methodaccording to claim 8, comprising: for supplying the second resin, afirst step of supplying a first insulating resin covering at least aside surface of the solder layer; and a second step of supplying asecond insulating resin covering the first insulating resin and fillinga predetermined gap between the circuit board and the semiconductorchip, wherein the second resin is composed of the first insulating resinand the second insulating resin.
 10. The flip chip mounting methodaccording to claim 9, further comprising the step of provisionallycuring the first insulating resin after the first step.
 11. The flipchip mounting method according to claim 9, wherein the first insulatingresin covers at least a side surface of the solder layer due to surfacetension.
 12. The flip chip mounting method according to claim 9, whereinthe first insulating resin is made of a material having a modulus ofelasticity lower than that of the second insulating resin.
 13. The flipchip mounting method according to claim 1, wherein the solder resincomposition is a viscous body.
 14. (canceled)
 15. A flip chip mountingapparatus for flip chip mounting a semiconductor chip on a circuitboard, comprising: holding means for holding the circuit board and thesemiconductor chip; arrangement means for aligning the connectionterminals of the circuit board with the electrode terminals of thesemiconductor chip while holding the connection terminals and theelectrode terminals with a predetermined gap therebetween so that theconnection terminals and the electrode terminals are not in contact;heating means for heating at least the circuit board or thesemiconductor chip to a temperature at which solder powder in a solderresin composition made of the solder powder and a resin is melted;supply means for supplying the solder resin composition to thepredetermined gap across which the circuit board and the semiconductorchip are held, from at least one end face direction of the semiconductorchip by a capillary phenomenon; and curing means for curing the resin inthe solder resin composition.
 16. The flip chip mounting apparatusaccording to claim 15, wherein the supply means is a dispenser.
 17. Theflip chip mounting apparatus according to claim 15, wherein the holdingmeans uses aspiration.
 18. The flip chip mounting apparatus according toclaim 15, wherein the holding means holds the circuit board and thesemiconductor chip in such a manner that the circuit board and thesemiconductor chip are inclined.
 19. The flip chip mounting apparatusaccording to claim 15, wherein the heating means further comprisescooling means.
 20. The flip chip mounting apparatus according to claim15, further comprising inspection means for inspecting an electricalconnection between the semiconductor chip and the circuit board. 21-33.(canceled)